Cosmetic brush



FIG. 1 is a front perspective view of a cosmetic brush showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a left side elevation view thereof;

FIG. 5 is a right side elevation view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The dashed broken lines showing the handle in the drawings depict portions of the cosmetic brush that form no part of the claimed design. 

CLAIM The ornamental design for a cosmetic brush, as shown and described. 